In terms of thoughtful design, usability and enjoyment, this app is miles ahead of TrailRunner and Ascent. It made the best first impression of any app I've used before, and is more flexible for reporting by activity/date/distance etc. It's early days, and there are quite a few improvements to be made, but this seems destined to be the app of choice for GPS-using athletes.

Since it's not mentioned anywhere else, I'll note that the trial version is limited to saving only 5 activities, so don't import all your old data, spend time annotating it, and then take a week to think about whether or not to buy.